In the fields of Pergamino in Argentina's grain heartland, farmer Adrian Farroni is revving up his soybean harvest late, delayed by rains that along with low prices have led to the country's slowest soy sales in a decade. The South American country's slow pace selling the oilseed could strain the region's supply even as rival Brazil's crop is dented by major floods. Argentina is one of the biggest global exporters of soyoil and meal that are processed from soybeans.